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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Not specified
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: No GLP or purity info. Similar to OECD 404, well reported, but with deviations. No scores recorded at 48 hours.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1973
Report Date:
1973

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
yes
Remarks:
See principles of method if other than guideline
Principles of method if other than guideline:
Deviations:
- Shaved 2 days before testing, normally 24 hours.
- Test material applied for 24 hours. Normally only applied for 4 hours.
- Observation period only 7 days, should be 14 days.

The procedure adopted was the patch-test technique described in the "Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics" (1959) of the US Association of Food and Drug Officials (AFDO).
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
Six rabbits (3 males/3 females) of the New Zealand White strain, weighing 2 to 3 kg, were shaved on the whole back and flanks two days before treatment with an electric clipper. In order to prevent injuries by bites the rabbits were kept separately in V2A wire cages, where they had access to food (NAFAG, Gossau SG, rabbit food) and water ad libitum.

Test system

Type of coverage:
occlusive
Preparation of test site:
shaved
Vehicle:
not specified
Controls:
not specified
Amount / concentration applied:
The test material was applied to each side in quantities of 0.5 mL.
Duration of treatment / exposure:
24 hours
Observation period:
72 hours upon removal of patch.
Number of animals:
6 (3 males and 3 females)
Details on study design:
The shaven skin on the left side was slightly scarified immediately before treatment.
A gauze patch 2.5 x 2.5 cm was soaked with the test material and immediately applied to the prepared skin. The patch was covered with a plastic film 5 x 5 cm, which was fixed to the body with adhesive tape. The gauze patches were removed 24 hours after the application. The reaction of the skin was appraised upon removal and 72 hours after it, on the basis of the evaluation scheme.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
1
Max. score:
1
Reversibility:
not fully reversible within: 72 hours
Irritation parameter:
edema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
0
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0.5
Max. score:
2
Reversibility:
fully reversible within: 72 hours
Irritation parameter:
edema score
Basis:
animal #2
Time point:
24/48/72 h
Score:
1
Max. score:
2
Reversibility:
not fully reversible within: 72 hours
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0.5
Max. score:
1
Reversibility:
fully reversible within: 72 hours
Irritation parameter:
edema score
Basis:
animal #3
Time point:
24/48/72 h
Score:
3.5
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Irritation parameter:
erythema score
Basis:
animal #4
Time point:
24/48/72 h
Score:
0.5
Max. score:
1
Reversibility:
fully reversible within: 72 hours
Irritation parameter:
edema score
Basis:
animal #4
Time point:
24/48/72 h
Score:
3.5
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Irritation parameter:
erythema score
Basis:
animal #5
Time point:
24/48/72 h
Score:
0.5
Max. score:
1
Reversibility:
fully reversible within: 72 hours
Irritation parameter:
edema score
Basis:
animal #5
Time point:
24/48/72 h
Score:
3.5
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Irritation parameter:
erythema score
Basis:
animal #6
Time point:
24/48/72 h
Score:
0.5
Max. score:
1
Reversibility:
fully reversible within: 72 hours
Irritation parameter:
edema score
Basis:
animal #6
Time point:
24/48/72 h
Score:
3.5
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Score:
1.7
Irritant / corrosive response data:
The average oedema score at 24 hours for intact skin is 2.67. The average edema score at 72 hours is 2.33. As the mean score at both of these time points is greater than 2, the test material can be said to be irritating to skin.
Other effects:
The skin of the rabbits treated with the test material, showed a white to yellow colour and a slight to medium oedema.
These symptoms did not diminish or disappear during the 7-day observation period.

Any other information on results incl. tables

The results of the skin Irritation test are summarised in the attached table.

The primary Irritation Index as the measure of the acute skin irritation provoked by the test material is defined as the average of all the ratings found after 24 and 72 hours on the intact and slightly scarified skin. The primary Irritation Index of the test material was 1.7.

Applicant's summary and conclusion

Interpretation of results:
other: EU Criteria: H315: Cause skin irritation
Conclusions:
Looking at the table, the average oedema score at 24 hours for intact skin is 2.67. The average oedema score at 72 hours is 2.33. As the mean score at both of these time points is greater than 2, the test material can be said to be irritating to skin. The primary Irritation Index of the test material was 1.7.
Executive summary:

The primary Irritation Index as the measure of the acute skin irritation provoked by the test material is defined as the average of all the ratings found after 24 and 72 hours on the intact and slightly scarified skin.

The primary Irritation Index of the test material was 1.7.

This study is considered the most relevant and reliable study for this endpoint, although technically the results are unable to be used for classification purposes as readings were only taken at 24 and 72 hours and also the test material was left on longer than specified in the guideline. However the mean oedema scores at 24 and 72 hours are above the EU C&L cut-off criteria according to Regulation (EC) no 1272/2008 and so it is highly likely that the 48 hours reading would also be above this cut-off value, and so this study would be considered to be the worst case scenario used to classify as irritating to the skin, therefore this study will be used for classification purposes for this endpoint.